1. Field
Embodiments of the present invention generally relate to a magnetic read head for use in a hard disk drive.
2. Description of the Related Art
The heart of a computer is a magnetic disk drive which typically includes a rotating magnetic disk, a slider that has read and write heads, a suspension arm above the rotating disk and an actuator arm that swings the suspension arm to place the read and/or write heads over selected circular tracks on the rotating disk. The suspension arm biases the slider towards the surface of the disk when the disk is not rotating but, when the disk rotates, air is swirled by the rotating disk adjacent an air bearing surface (ABS) of the slider causing the slider to ride on an air bearing a slight distance from the surface of the rotating disk. When the slider rides on the air bearing, the write and read heads are employed for writing magnetic impressions to and reading magnetic signal fields from the rotating disk. The read and write heads are connected to processing circuitry that operates according to a computer program to implement the writing and reading functions.
The read head typically utilizes a spin valve sensor, also referred to as a magnetoresistive (MR) sensor. The sensor at the ABS typically includes a barrier layer sandwiched between a pinned layer and a free layer. The magnetization of the pinned layer is pinned perpendicular to the ABS and the magnetic moment of the free layer is located parallel to the ABS, but free to rotate in response to external magnetic fields.
In order to respond to the demand for even higher density recording in recent years, the effective track width of magnetoresistive sensors has been made narrower, but this has caused the element resistance to increase, the noise to increase, and sensitivity to reduce, and has produced the separate issue that it is difficult to increase the sensitivity. Therefore, there is a need for an improved magnetic head and method of manufacture.